21385534 has 12 divisors (see below), whose sum is σ = 32847336. Its totient is φ = 10442292.

The previous prime is 21385513. The next prime is 21385549. The reversal of 21385534 is 43558312.

It is a junction number, because it is equal to n+sod(n) for n = 21385496 and 21385505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 807 + ... + 6589.

It is an arithmetic number, because the mean of its divisors is an integer number (2737278).

Almost surely, 2^21385534 is an apocalyptic number.

21385534 is a deficient number, since it is larger than the sum of its proper divisors (11461802).

21385534 is an equidigital number, since it uses as much as digits as its factorization.

21385534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5871 (or 5828 counting only the distinct ones).

The product of its digits is 14400, while the sum is 31.

The square root of 21385534 is about 4624.4495888700. The cubic root of 21385534 is about 277.5705374889.

The spelling of 21385534 in words is "twenty-one million, three hundred eighty-five thousand, five hundred thirty-four".